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Oxide Inclusions at Different Steps of Steel Production

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Journal of Iron and Steel Research International 2007年第5期14卷 39-46页

作者： yousef payandeh Mansour Soltanieh Department of Materials and Metallurgical Engineering Iran University of Science and Technology

The formation of oxide inclusions in one of the carbon steel productions of Mobarakeh Steel Complex of Isfahan has been evaluated. Several samples from different steps of steel production were taken, from arc furnace, ladle furnace, tundish, and continuous casting mold. Moreover, samples of slab and hot rolling products were prepared. The samples were investigated by optical and scanning electron microscopes equipped with the EDS system. According to the results, the number, composition, and kind of inclusions were directly influenced by the production variables. It was found that when the amount of dissolved oxygen was high （say more than 0. 002 5%）, the dissolved aluminum was able to reduce silicon oxide and react with the dissolved oxygen simultaneously, whilst, the dissolved aluminum could reduce the magnesium oxide only when the oxygen content was below 0. 000 5%. Based on this research, a mechanism for forming the complex inclusions was suggested. It was also found that if the aluminum is added to the melt as late as possible, a cleaner melt with fewer inclusions is prepared; this method will be more effective, especially in the case of complex inclusions.

关键词： inclusion deoxidation steel quality complex inclusion

Modeling forest fires in Mazandaran Province, Iran

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Journal of Forestry Research 2015年第4期26卷 851-858页

作者： Amir T.payandeh Najafabadi Fatemeh Gorgani Maryam Omidi Najafabadi Faculty Member of Department of Mathematical Sciences Shahid Beheshti University Department of Basic Sciences Payame Noor University Centre Faculty Member of Department of Agricultural Sciences Science and Research Branch Islamic Azad University

We used a spafio-temporal shot-noise Cox process to study the distribution of forest fires reported between 2006 and 2010 in the Mazandaran Province＇s forests. The fitted model shows that daily temperature, altitude, and slope-exposure impacted fire occurrence. Forest fire occurred in the region had an aggregated behavior, which increased in radius below 1-km away from fired areas; a periodic pattern of fire occurrence in the region was verified. The risk of forest fire is significantly higher for areas with southern exposure and slope between 30° and 50°, northern exposure and slope between 0° and 50°, and eastern exposure and slope between 0° and 30°. The risk of fire was also significantly higher at altitudes between 1350 and 3000 m asl. Human causes were the main ignition source for forest fires in the region. The fire occurrence rate stayed above average during the drought period from September 2008 to September 2009. Our findings could lead to the development of fire-response and fire-suppression strategies appropriate to specific regions.

关键词： Forest fire Spatio-temporal shot-noise Coxprocesses Spatial point process

On the role of surface carbonate species in determining the cycling performance of all-solid-state batteries

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Materials Futures 2022年第2期1卷 116-120页

作者： Florian Strauss Seyedhosein payandeh Aleksandr Kondrakov Torsten Brezesinski Battery and Electrochemistry Laboratory(BELLA) Institute of NanotechnologyKarlsruhe Institute of Technology(KIT)Hermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany BASF SE Carl-Bosch-Str.3867056 LudwigshafenGermany

This short perspective summarizes recent findings on the role of residual lithium present on the surface of layered Ni-rich oxide cathode materials in liquid-and solid-electrolyte based batteries,with emphasis placed on the carbonate *** and future research opportunities in the development of carbonate-containing protective nanocoatings for inorganic solid-state battery applications are also discussed.

关键词： electrochemical energy storage layered oxide cathode materials protective coatings surface contaminants interfacial chemistry

One-loop approximation of Mφller scattering in generalized Krein-space quantization

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Science China(Physics,Mechanics & Astronomy) 2009年第2期52卷 212-217页

作者： F. payandeh M. MEHRAFARIN M. V. TAKOOK Physics Department Amirkabir University of Technology Payame Noor University Physics Department Razi University

It has been shown that the negative-norm states necessarily appear in a covariant quantization of the free minimally coupled scalar field in de Sitter spacetime. In this processes ultraviolet and infrared di- vergences have been automatically eliminated. A natural renormalization of the one-loop interacting quantum field in Minkowski spacetime (λφ 4) has been achieved through the consideration of the nega- tive-norm states defined in Krein space. It has been shown that the combination of quantum field theory in Krein space together with consideration of quantum metric fluctuation, results in quantum field the- ory without any divergences. Pursuing this approach, we express Wick’s theorem and calculate Mφller scattering in the one-loop approximation in generalized Krein space. The mathematical consequence of this method is the disappearance of the ultraviolet divergence in the one-loop approximation.

关键词： quantum field theory Krein space negative energy states

A Krein quantization approach to Klein paradox

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Chinese Physics C 2013年第11期37卷 14-19页

作者： Farrin payandeh Toradj Mohammad Pur Mohsen Fathi Zahra Gh.Moghaddam Department of Physics Payame Noor UniversityPO BOX 19395-3697 Tehran Iran Department of Physics Payame Noor UniversityTabriz Iran Department of Physics Islamic Azad University Central Tehran BranchTehran Iran

In this paper we first introduce the famous Klein tization approach and taking the negative modes into account densities could be achieved without confronting any paradox. paradox. Afterwards by proposing the Krein qu... 详细信息

关键词： Klein paradox negative energies Krein quantization

On Point-Based Haptic Rendering

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Engineering（科研） 2013年第5期5卷 14-24页

作者： Shi Wen Shahram payandeh Experimental Robotics and Haptics Laboratory Simon Fraser University Burnaby Canada

Haptic rendering is referred to as an approach for complementing graphical model of the virtual object with mechanics- based properties. As a result, when the user interacts with the virtual object through a haptic device, the object can graphically deflect or deform following laws of mechanics. In addition, the user is able to feel the resulting interaction force when interacting with the virtual object. This paper presents a study of defining the levels-of-detail (LOD) in point-based computational mechanics for haptic rendering of objects. The approach uses the description of object as a set of sampled points. In comparison with the finite element method (FEM), point-based approach does not rely on any predefined mesh representation and depends on the point representation of the volume of the object. Different from solving the governing equations of motion representing the entire object based on pre-defined mesh representation which is used in FEM, in point-based modeling approach, the number of points involved in the computation of displacement/deformation can be adaptively defined during the solution cycle. This frame work can offer the implementation of the notion for levels-of-detail techniques for which can be used to tune the haptic rendering environment for in- creased realism and computational efficiency. This paper presents some initial experimental studies in implementing LOD in such environment.

关键词： Haptic Rendering Computational Mechanics Point-Based Modeling Level-of-Details

Calculation of the Approximate Energy of Ground and Excited Stationary States in Quantum Mechanics Using Delta Method

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Journal of Applied Mathematics and Physics 2016年第1期4卷 130-139页

作者： Farrin payandeh Touraj Mohammadpour Department of Physics Payame Noor University (PNU) Tehran Iran

In this paper, pursuing a new advised method called Delta method which is basically similar to variational method, we find the ground and excited states, according to a typical quantum Hamiltonian. Moreover, applying this method, the upper bound values for the eigenenergies of the so-called ground and excited states are estimated. We will show that this new method, is as beneficial as the traditional variational method which is common in deriving eigenenergies of some of the quantum Hamiltonians. This method helps physics students to broaden their knowledge about the possible mathematical ways;they can use to obtain eigenenergies of some quantum Hamiltonians. The advantage of Delta method to variational method is in its simplicity and reduction of the calculation procedures.

关键词： Quantum Mechanics Eigenenergies Alternative Methods Delta Method

Tailoring the LiNbO_(3)coating of Ni-rich cathode materials for stable and high-performance all-solid-state batteries

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Nano Research Energy 2022年第3期1卷 4-10页

作者： Seyedhosein payandeh Florian Strauss Andrey Mazilkin Aleksandr Kondrakov Torsten Brezesinski Battery and Electrochemistry Laboratory Institute of NanotechnologyKarlsruhe Institute of Technology(KIT)Hermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany Karlsruhe Nano Micro Facility Karlsruhe Institute of Technology(KIT)Hermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany BASF SE Carl-Bosch-Str.3867056 LudwigshafenGermany

The research and development of advanced nanocoatings for high-capacity cathode materials is currently a hot topic in the field of solid-state batteries(SSBs).Protective surface coatings prevent direct contact between the cathode material and solid electrolyte,thereby inhibiting detrimental interfacial decomposition *** is particularly important when using lithium thiophosphate superionic solid electrolytes,as these materials exhibit a narrow electrochemical stability window,and therefore,are prone to degradation during battery *** we show that the cycling performance of LiNbO_(3)-coated Ni-rich LiNi_(x)Co_(y)Mn_(z)O_(2)cathode materials is strongly dependent on the sample history and(coating)synthesis *** demonstrate that post-treatment in a pure oxygen atmosphere at 350℃results in the formation of a surface layer with a unique microstructure,consisting of LiNbO_(3)nanoparticles distributed in a carbonate *** tested at 45℃and C/5 rate in pellet-stack SSB full cells with Li_(4)Ti_(5)O_(12)and Li_(6)PS_(5)Cl as anode material and solid electrolyte,respectively,around 80%of the initial specific discharge capacity is retained after 200 cycles(~160 mAh·g^(−1),~1.7 mAh·cm^(−2)).Our results highlight the importance of tailoring the coating chemistry to the electrode material(s)for practical SSB applications.

关键词： solid-state battery layered Ni-rich oxide cathode superionic solid electrolyte protective surface coating side reactions

The interplay between (electro)chemical and (chemo)mechanical effects in the cycling performance of thiophosphate-based solid-state batteries

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Materials Futures 2022年第1期1卷 122-134页

作者： Jun Hao Teo Florian Strauss Felix Walther Yuan Ma Seyedhosein payandeh Torsten Scherer Matteo Bianchini Jürgen Janek Torsten Brezesinski Battery and Electrochemistry Laboratory Institute of NanotechnologyKarlsruhe Institute of Technology(KIT)Hermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany Institute of Physical Chemistry&Center for Materials Research Justus-Liebig-University GiessenHeinrich-Buff-Ring 1735392 GiessenGermany KNMF Laboratory for Micro-and Nanostructuring Institute of NanotechnologyKarlsruhe Institute of Technology(KIT)Hermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany BASF SE Carl-Bosch-Str.3867056 LudwigshafenGermany

Solid-state batteries(SSBs)are a promising next step in electrochemical energy storage but are plagued by a number of *** this study,we demonstrate the recurring issue of mechanical degradation because of volume changes in layered Ni-rich oxide cathode materials in thiophosphate-based ***,we explore superionic solid electrolytes(SEs)of different crystallinity,namely glassy 1.5Li_(2)S-0.5P_(2)S_(5)-LiI and argyrodite Li_(6)PS_(5)Cl,with emphasis on how they affect the cyclability of slurry-cast cathodes with NCM622(60%Ni)or NCM851005(85%Ni).The application of a combination of ex situ and in situ analytical techniques helped to reveal the benefits of using a SE with a low Young’s *** a synergistic interplay of(electro)chemical and(chemo)mechanical effects,the glassy SE employed in this work was able to achieve robust and stable interfaces,enabling intimate contact with the cathode material while at the same time mitigating volume *** results emphasize the importance of considering chemical,electrochemical,and mechanical properties to realize long-term cycling performance in high-loading SSBs.

关键词： solid-state battery slurry casting lithium thiophosphate electrolyte Ni-rich NCM cathode degradation